【作者】 辛向阳；

【导师】 孙丰源；

【作者基本信息】 天津医科大学 ， 眼科学（专业学位）， 2014， 博士

【摘要】 第一部分应用HR-MRI对正常眼眼外肌、泪腺、眼球容积生物测量的研究目的应用HR-MRI技术对正常人眼部结构进行活体生物测量,获取在活体状态下眼部组织结构形态及其精确数值,建立正常眼活体组织测量值,为眼科研究、教学及临床诊断提供理论数据。方法选择正常志愿者100例(200眼眶),其中男性50例(100眼眶),女性50例(100眼眶),所有受试者均行HR-MRI眼眶扫描,并应用图像处理软件进行相关参数测量分析：1、眼外肌肌腹最大径层面的水平径及垂直径。2、眼眶直肌坐标值及眼球动态直肌横截面积。3、泪腺MRI表现及测量。4、眼球容积。结果1、正常国人两侧眼外肌对称,且粗细有一定的规律,最大径线层面内各条眼外肌短径大小关系：下直肌>内直肌>上直肌>外直肌；长径大小关系：外直肌>内直肌>上直肌>下直肌。2、(1)原在位时,相对于眼眶中心的坐标值分别为内直肌(12.53mm,-2.25mm);外直肌(-14.35mm,-2.86mm);上直肌(1.9mm,12.00mm)；下直肌(4.80mm,-11.40mm);(2)原在位及4条直肌收缩和松弛时,在MRI图像上直肌最大横截面积所在层面位于眼球-视神经连接平面后6mm处；(3)直肌收缩和松弛时,MRI图像上横截面积变化幅度由大到小依次为上直肌、下直肌、内直肌、外直肌。3、在T2WI上85例泪腺与脑白质信号相近,15例泪腺信号略高；在T1WI上泪腺与脑白质信号相近；在T1WI脂肪抑制序列,泪腺呈高信号；男性泪腺面积左、右两侧间无明显差异,女性泪腺面积左、右两侧间有显著差异,右侧略大,泪腺面积无明显性别间差异；男性眶缘前部泪腺面积比率(Sr)值左、右两侧间无明显差异,女性Sr值左、右两侧间有显著差异,左侧大于右侧；男、女性的Sr值均随年龄增加而增大,Sr值无明显性别间差异。4、所测的容积值：玻璃体腔容积4.514±0.323cm3,与“眼科测量正常值”比较,差异无统计学意义(P=0.148)。球内总容积、眼房水容积、晶状体容积分别为5.146±0.352cm3.0.244±0.385cm3、0.223±0.222cm3,与“眼科测量正常值”比较,差异有统计学意义(P<0.001)。结论1、判断眼外肌大小是否正常可利用双侧眼外肌对称性及眼外肌粗细规律来判断。2、正常人原在位MRI图像4条直肌横截面中心在眼眶内坐标值及4条直肌收缩和松弛时横截面积变化的正常比值的建立,为眼外肌病的MRI诊断及手术治疗提供了参考。3、MRI横断面及冠状面均可以清楚显示泪腺,非增强T1WI脂肪抑制序列可较好地显示泪腺的形态、结构、位置及与邻近结构的关系；双侧泪腺的大小、形态并不完全对称；随着年龄的增长,泪腺可有向前、下、外方的移位；泪腺大小、位置无明显性别间差异。4、MRI可较好的应用于活体眼球容积的测量。所测玻璃体腔容积与“眼科测量正常值”之间差异不显著；球内总容积小于“眼科测量正常值”；眼前房及晶状体稍大于“眼科测量正常值”。第二部分不同年龄正常眼眶容积的MRI测量目的探讨正常眼眶容积的发育规律,建立中国人群眼眶容积磁共振扫描(MRI)测量的正常参考值。方法选择100例眼部无阳性病征,男性50例、女性50例,根据年龄分组,应用磁共振扫描技术,在眼眶的横断、冠状及平行视神经的斜矢状位扫描,计算眼眶容积,分析眼眶容积与年龄、性别的关系。结果眼眶容积在各年龄阶段左右对称,20岁之前眼眶容积增长迅速,大约男性17岁、女性13岁时平均眼眶容积分别为25.59ml、23.64m1,达正常成年人眶容积的95%,正常成人眼眶容积男性大于女性,男女性平均眼眶容积分别为27.22±3.27ml、24.88±3.04ml。眼眶容积与年龄呈显著正相关(P<0.05),但14岁之前男女性眼眶容积比较差异无统计学意义(P>0.05)。结论正常人眼眶容积左右对称,其大小与年龄、性别有关,且20岁之前增长迅速,40岁之后仍缓慢增长。更多还原

【Abstract】 Part Ⅰ Study on normal ophthalmic tissues among EONs、lacrimal gland and ocular volume structure measurement by High-Resolution MRIObjective The HR-magnetic resonance imaging (MRI) technology was applied to measure the ocular structures of healthy people in order to establish database for ocular structures and provide theoretical support for eye research, teaching and diagnosis.Methods Choose100cases of normal volunteers (200orbits),50cases of male (100orbits),50cases of female orbital (100orbits), all the subjects accepted line HR-orbital MRI, and image processing software was applied to morphology and statistical analysis.1. Measurement of extraocular muscle, muscle belly level horizontal diameter and maximum diameter vertical diameter.2. Eye rectus coordinates, and eye dynamic rectus muscle cross-sectional area.3. The MRI manifestation of lacrimal gland and measurement.4. Eye volume measurementResults l.The EOMs of normal Chinese were symmetrical on the two sides, and following a certain rule. The relationships of the short diameters of EOMs in the Maximum Planes were:IR>MR>SR>LR. That of the long diameters of EOMs were: IR>MR>SR>IR.2.(1) In the primary position, on the plane of eye-optic nerve cross, the coordination of the medial rectus, lateral rectus, superior rectus and inferior rectus muscle relative to the orbital center are (12.53mm,-2.25mm),(-14.35mm,-2.86mm),(1.90mm,12.00mm),(4.80mm,-11.40mm);(2) In the primary position, left, right, up, down gaze, the largest cross-section of the rectus muscles is on the plane of6mm posterior to the plane of eye-optic nerve cross on the images of coronal MRI scan;(3) When the rectus contact and relax, the most obvious change of cross-section is the superior rectus muscle, followed by the inferior rectus, the medial rectus and the lateral rectus muscle, respectively.3.On T2WI the lacrimal gland showed isointensity signal in85and hyperintensity signal in15subjects with respect to the cerebral white matter. On T1WI, the lacrimal gland showed isointensity signal. OnT1WI+FS, the lacrimal gland showed hyperintensity signal. There was no significant difference in the area of the lacrimal gland between sides in men. But in women, the area of the right lacrimal gland was larger than that of left lacrimal. No significant difference was observed in the area of the lacrimal gland between the men and women. There was no significant difference in the Sr of the lacrimal gland between sides in men. But in women, the Sr of the left side lacrimal gland was larger than that of right side. The Sr showed an age-related increase in both men and women.4. The volume of the vitreous cavity4.514±0.323cm3was little different from the anatomic normal value(P=0.148); The volumes of the ocular globe, the anterior chamber, and the lens cavity were5.146±0.352cm3,0.244±0.385cm3,0.223±0.222cm3, with no statistic differences compared with those of the anatomic normal values.Conclusions1.Sizes of EOMs can be assessed by the symmetry on the two sides and by observing the usual rule of EOMs2.We established the rectus muscle coordination of the normal Chinese on the image of coronal orbit MRI and the rate of the cross-section change when the rectus contract and relax in this study, which may help us to diagnose and treat the strabismus.3. Both axial and coronal planes of MR imaging could demonstrate clearly the lacrimal gland. The intensity of the lacrimal gland was similar to the cerebral white matter. Non-enhanced T1WI+FS sequence could show the configuration structure、location and adjacent tissues of the lacrimal gland clearly. Bilateral lacrimal glands were not symmetrical exactly. Lacrimal gland may have anterior、inferior and lateral displacement with age increased.4. MRI could be used for measuring ocular volume. Compared with the anatomic normal value, there was no significant difference in the vitreous cavity volume although the volumes of the lens and the anterior chamber seemed a little bigger.Part Ⅱ Study on the growth of orbital volume in individuals at different ages by MRIObjective To study the growth aspects of orbital volume and to establish the normal value of orbital volume by magnetic resonance imaging (MRI).Method One hundred individuals without eye diseases (50males,50females) were divided into5groups according to the age. Orbital volume and length of horizontal transverse axis and anterior-posterior axis of the eye were measured at different age in MRI. The relationship between orbital volume and age, gender was analyzed. Results There was no difference between the left and right orbital volume in all age groups. Orbital volume grew rapidly before20years of old. Mean orbital volume inmales aged17and females aged13was25.59and23.64ml, respectively, which reached95%of the adult orbital volume. In normal adult, orbital volume in the male was larger than that of the female. The mean orbital volume of adult male and female was27.22±3.37ml and24.88±3.04ml, respectively. A strong linear correlation was presented between the age and orbital volume (P<0.05). If stratified by age, the difference of orbital volume between the male and female was found not to be significant before14(P>0.05).Conclusions There is no remarkable difference between the right and left orbital volume. Orbital volume is associated with age and gender. Orbital volume grows rapidly before20and still grows slowly after40.更多还原